Cincinnati Bengals coach Marvin Lewis was not with his team for Tuesday’s practice, and the Bengals have announced that he is tending to a health concern.

In a statement released to media and on the team’s Twitter account, the Bengals said, “Coach Marvin Lewis will be taking time away from the team to focus on a minor health issue. He will be back as soon as possible, which could be today [Tuesday] or later this week. Special Teams Coordinator Darrin Simmons will lead the team during Coach Lewis’ absence.”

NFL Network’s Stacey Dales reported via Twitter that Lewis is dealing with a blood cyst in his ankle, citing a source close to Lewis.

Cincinnati coach Marvin Lewis is taking a short absence from his team to deal with a health issue. (AP)Lewis, who will turn 59 on Sept. 23, is the second-longest tenured head coach in the NFL; this is his 15th season with the Bengals.

It is unclear whether Lewis will be back with the team for Friday’s preseason opener against the Tampa Bay Buccaneers.

Simmons has been on Lewis’ staff since Lewis was hired in Cincinnati in 2003.

Lewis isn’t the first NFL coach to miss time recently because of health concerns: Minnesota Vikings coach Mike Zimmer has missed time with an ongoing eye problem that has so far required eight surgeries; Bruce Arians of the Arizona Cardinals dealt with various ailments including kidney cancer over the last year; and former Denver Broncos coach Gary Kubiak missed a game last season due to what was termed a “complex migraine.” Kubiak retired after the season, citing his health as a reason why he was leaving the sideline at just 55 years old.